CompactPCI Serial is an industrial standard for modular computer systems. It is based on the established PICMG 2.0
CompactPCI
CompactPCI is a computer bus interconnect for industrial computers, combining a Eurocard-type connector and PCI signaling and protocols. Boards are standardized to 3 U or 6U sizes, and are typically interconnected via a passive backplane. The ...
standard, which uses the parallel
PCI bus for communication among a system's card components. In contrast to this, CompactPCI Serial uses only serial
point-to-point connections.
CompactPCI Serial was officially adopted by the PCI Industrial Computer Manufacturers Group
PICMG
PICMG, or PCI Industrial Computer Manufacturers Group, is a consortium of over 140 companies. Founded in 1994, the group was originally formed to adapt Conventional PCI, PCI technology for use in high-performance telecommunications, military, an ...
as PICMG CPCI-S.0 CompactPCI Serial in March 2011. Its mechanical concept is based on the proven standards of IEEE 1101-1-1998 and IEEE 1101-10-1996 (19" technology). CompactPCI Serial includes different connectors that permit very high data rates.
The new technology standard succeeding parallel CompactPCI comprises another specification called PICMG 2.30 CompactPCI PlusIO. This is why CompactPCI Serial and CompactPCI PlusIO as a whole were also called CompactPCI Plus. PICMG's first working title of CompactPCI Serial was CPLUS.0. (See also
#Compatibility and Migration.)
CompactPCI Serial backplanes and chassis are developed by
Schroff,
Elmа, and Pixus Technologies companies, as for the CompactPCI Serial board level electronics – they are developed by
MEN Mikro Elektronik,
Fastwel,
EKF,
Emerson Embedded Computing,
ADLINK
ADLINK Technology Inc. ( ) is a company that designs and manufactures products for embedded computing, test and measurement, and automation applications. ADLINK's product line includes computer-on-modules, industrial motherboards, data acquisition ...
, and
Kontron.
History
Fast serial point-to-point connections have become the state-of-the-art technology and are gradually replacing the classic bus architecture in computers. The CompactPCI standard as it is now does not offer a standardized solution for the kind of modular, serial connectivity requested for the future. This is why CompactPCI Serial was defined as the new future standard. It introduces a serial topology while keeping the proven basic concepts of CompactPCI.
Star Topology
Thanks to modern chipset architecture, the structure of computers is slowly changing from bus-based interconnections between interface controllers to a
star topology built up of serial point-to-point connections. CompactPCI Serial incorporates this star architecture: one system slot can control up to eight peripheral slots. Two of these connections can be PCI Express x8
fat pipes. At the same time, CompactPCI Serial does not need bridges, switched fabrics, or special backplanes.
The star connection by standard includes PCI Express, SATA/SAS, and USB.
Ethernet Full Mesh Architecture
CompactPCI Serial can connect a total of nine cards in a system (one system slot, eight peripheral) through a full Ethernet
mesh
A mesh is a barrier made of connected strands of metal, fiber, or other flexible or ductile materials. A mesh is similar to a web or a net in that it has many attached or woven strands.
Types
* A plastic mesh may be extruded, oriented, ex ...
that supports the
IEEE 802.3 Ethernet standard. In this way the new specification is optimized for symmetrical
multiprocessing
Multiprocessing is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to the ability of a system to support more than one processor or the ability to allocate tasks between them. There ar ...
and
redundant system topologies.
Interfaces
The PICMG CPCI-S.0 system slot supports the following interfaces at the backplane connectors:
* 8 x
PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common ...
** 6 x4 links
** 2 x8 links (fat pipes)
** 2 dedicated
I²C
I2C (Inter-Integrated Circuit, ), alternatively known as I2C or IIC, is a synchronous, multi-controller/multi-target (master/slave), packet switched, single-ended, serial communication bus invented in 1982 by Philips Semiconductors. It is wi ...
high-speed buses for the fat pipes
** Optional serial
RapidIO
The RapidIO architecture is a high-performance packet-switched electrical connection technology. RapidIO supports messaging, read/write and cache coherency semantics. Based on industry-standard electrical specifications such as those for Ether ...
* 8 x
SATA
SATA (Serial AT Attachment) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Serial ATA succeeded the earlier Parallel ATA (PATA) standard t ...
/
SAS
** Supported by
SGPIO
Serial general purpose input/output (SGPIO) is a four-signal (or four-wire) bus used between a host bus adapter (HBA) and a backplane. Of the four signals, three are driven by the HBA and one by the backplane. Typically, the HBA is a storage con ...
bus (
SFF-8485 specification) for
hot swapping
Hot swapping is the replacement or addition of components to a computer system without stopping, shutting down, or rebooting the system; hot plugging describes the addition of components only. Components which have such functionality are said ...
* 8 x
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
2.0
* 8 x USB 3.0
* 8 x
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
10GBASE-T
* Optional hot swap support by one dedicated I²C bus
* Optional
IPMI support by one dedicated I²C bus
The PICMG CPCI-S.0 peripheral slot supports the following interfaces at the backplane connectors:
* 1 x PCI Express
** Up to 8 lanes per link
* 1 x SATA
** Supported by a dedicated SGPIO bus (SFF-8485 specification)
* 1 x USB 2.0
* 1 x USB 3.0
* Up to 8 Ethernet 10GBASE-T interfaces
* Geographical addressing
Power Supply of CompactPCI Serial
PICMG CPCI-S.0 defines a single 12-V power supply both for system slots and peripheral slots.
Backplane Connectors of CompactPCI Serial
The PICMG subcommittee drafting the standard has proposed a new, denser backplane connector type with a 2 mm x 1.4 mm pitch that supports higher transfer rates of up to 12 Gbit/s without a need for bridges or switches. It offers up to 184 pin pairs on a 3U board.
A major difference compared to CompactPCI is that with CompactPCI Serial the plug connector is on the board, while the receptacle is on the backplane. This approach is intended to make the standard more robust by avoiding twisted pins on the backplane: If a pin fails, only the plug-in board must be exchanged.
The system slot of CompactPCI Serial has six connectors: P1 to P6.
On peripheral boards only P1 is mandatory, while P2 to P6 are optional.
Rear I/O Concept
A peripheral CompactPCI Serial slot only has a small connector with 6 rows of contacts for power and signals. The remainder of a 3U single Eurocard is free for user-defined I/O and offers a total of 128 differential contact pairs or 384 contacts. This is significantly more than in 32-bit CompactPCI.
6U double Eurocards provide the entire upper section of the board for user-defined I/O, as do PICMG 2.0 CompactPCI boards of this size. An advantage of the new architecture is that front and rear I/O boards are inserted directly into one another. By contrast to CompactPCI, no
midplane or transfer connector is needed here, which reduces costs and increases system flexibility.
Compatibility and Migration
The mechanical specification of PICMG CPCI-S.0 CompactPCI Serial is 100% compliant with PICMG 2.0 CompactPCI except for its new backplane connectors. Since the two standards have a different topology, there is no direct "bus compatibility". For this reason, PICMG has also created an extension to CompactPCI:
PICMG 2.30 CompactPCI PlusIO. This standard is intended as a migration path from CompactPCI to CompactPCI Serial. It is 100% compatible with CompactPCI but includes a fixed definition of fast serial I/O interfaces at its backplane J2 connector. Also, it has a new J2 connector that is compatible but supports higher data rates compared to CompactPCI.
Hybrid backplanes support several cards of the three different standards PICMG 2.0, 2.30, and CPCI-S.0.
CompactPCI Serial Space
In August 2017, PICMG ratified the CompactPCI Serial Space specification CPCI-S.1 R1.0, which provides a highly ruggedized implementation of CompactPCI Serial. It is used in satellites as the payload controller as well as ground-based control systems.
See also
*
CompactPCI
CompactPCI is a computer bus interconnect for industrial computers, combining a Eurocard-type connector and PCI signaling and protocols. Boards are standardized to 3 U or 6U sizes, and are typically interconnected via a passive backplane. The ...
*
CompactPCI PlusIO
CompactPCI PlusIO is an extension to the PICMG 2.0 CompactPCI industrial standard for modular computer systems.
CompactPCI PlusIO was officially adopted by the PCI Industrial Computer Manufacturers Group PICMG as PICMG 2.30 CompactPCI PlusIO in No ...
*
PICMG
PICMG, or PCI Industrial Computer Manufacturers Group, is a consortium of over 140 companies. Founded in 1994, the group was originally formed to adapt Conventional PCI, PCI technology for use in high-performance telecommunications, military, an ...
*
VPX
VPX (Virtual Path Cross-Connect), also known as VITA 46, refers to a set of standards for connecting components of a computer (known as a computer bus), commonly used by defense contractors.
Some are ANSI standards such as ANSI/VITA 46.0–2019.
...
References
External links
*
{{Computer bus
Peripheral Component Interconnect
PICMG standards